package cn.wolfcode.service.impl;

import cn.wolfcode.domain.Permission;
import cn.wolfcode.mapper.PermissionMapper;
import cn.wolfcode.qo.QueryObject;
import cn.wolfcode.service.IPermissionService;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.apache.shiro.authz.annotation.RequiresPermissions;
import org.springframework.aop.support.AopUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Controller;
import org.springframework.stereotype.Service;

import java.lang.reflect.Method;
import java.util.*;

@Service
public class PermissionServiceImpl implements IPermissionService {

    @Autowired
    private PermissionMapper permissionMapper;

    @Override
    public void save(Permission permission) {
        permissionMapper.insert(permission);
    }

    @Override
    public void delete(Long id) {
        permissionMapper.deleteByPrimaryKey(id);
    }

    @Override
    public void update(Permission permission) {
        permissionMapper.updateByPrimaryKey(permission);
    }

    @Override
    public Permission get(Long id) {
        return permissionMapper.selectByPrimaryKey(id);
    }

    @Override
    public List<Permission> listALL() {
        return permissionMapper.selectAll();
    }

    @Override
    public PageInfo<Permission> query(QueryObject qo) {
        PageHelper.startPage(qo.getCurrentPage(),qo.getPageSize());
        List<Permission> permissions = permissionMapper.selectForList(qo);
        return new PageInfo<Permission>(permissions);
    }

    @Autowired
    private ApplicationContext ctx; //spring上下文对象

    @Override
    public void reload() {
        //需求：把每个控制器中的贴了权限注解的方法转化为权限数据，并插入到数据库
        //查询数据库中已经有的权限表达式
        List<String> permissions = permissionMapper.selectAllExpression();
        //1.获取所有的控制器
        Map<String, Object> map = ctx.getBeansWithAnnotation(Controller.class);
        Collection<Object> controllers = map.values();
        //2.遍历获取每个控制器中的方法
        for (Object controller : controllers) {
            //如果controller是普通的controller类，它的父类就object，object的方法也没有贴注解，效果不影响，就是效率不高
            //判断是否cglib代理对象,如果不是，就跳过
            if(!AopUtils.isCglibProxy(controller)){
                 continue;
            }
            //代理对象中的方法上的注解不能被继承，所以获取不到注解
            //控制器的字节码对象(controller是代理对象，获取他的父类，就可以拿到注解)
            Class<?> clazz = controller.getClass().getSuperclass();
            //3.遍历获取到每个方法
            Method[] methods = clazz.getDeclaredMethods();
            for (Method method : methods) {
                //4.判断该方法是否有贴自定义的注解（shiro提供的）
                RequiresPermissions annotation = method.getAnnotation(RequiresPermissions.class);
                if(annotation!=null){
                    //5.从注解中获取权限相关的数据，并封装为权限对象
                    String name = annotation.value()[1];
                    // 方式一：从注解中获取权限表达式
                     String expression = annotation.value()[0];
                    // 方式二：通过反射拼接出来
                  /*  String simpleName = clazz.getSimpleName(); //EmployeeController
                    simpleName = simpleName.replace("Controller", ""); //Employee
                    simpleName = StringUtils.uncapitalize(simpleName); //employee
                    String expression = simpleName + ":" + method.getName(); //employee:delete*/

                    if(!permissions.contains(expression)){ //权限表达式集合中不包括这个权限表达式，就需要插入
                        //6.插入到数据库
                        Permission permission = new Permission();
                        permission.setName(name);
                        permission.setExpression(expression);
                        permissionMapper.insert(permission);
                    }
                }
            }
        }
    }

    @Override
    public List<String> selectExpressionByEmpId(Long id) {
        return permissionMapper.selectExpressionByEmpId(id);
    }

}
